Local area networks have been developed for digital communication between computers and other types of digital systems. The networks have been standardized to some extent to facilitate communication between equipment of different manufacturers. Among these networks are Ethernet and IEEE 802.3. Ethernet is a registered trademark of the Xerox Corporation. These systems include a communication bus which carries two-way digital communications. A host system is connected to the network by means of a transceiver circuit which transmits data from the host system onto the communication bus and receives data from the communication bus and forwards it to the host system. The transceiver circuit also generally includes circuitry for detecting collisions between transmitted and received signals. In addition, the transceiver circuit may contain circuitry for testing the collision presence detector. This test is known as the "heartbeat" test.
In the installation, maintenance and troubleshooting of the transceiver portion of a network system, elaborate diagnostic test instruments and software can be utilized to assist in verifying proper operation and in pinpointing problems. However, we have found that in many cases, the problems are relatively simple and that the use of complex test instruments and software is unnecessary. However, in the past, simple and easy-to-interpret transceiver troubleshooting devices have not been available. One of the difficulties in providing a simple and low-cost indicator of transceiver operation is that the signals carried on the network bus are high speed digital data signals which cannot readily be interpreted except with the use of complex and expensive test equipment to synchronize and evaluate the data signals.
It is a general object of the present invention to provide improved transceiver apparatus for interfacing between a host system and a communication bus.
It is a another object of the present invention to provide a communication transceiver assembly with visual indicators which readily indicate the operating status of the assembly.
It is a further object of the present invention to provide a communication network transceiver assembly with a simple and low-cost means to assist troubleshooting and maintenance.